Dicing wafers having solder bumps on wafer backside

Abstract

Approaches for hybrid laser scribe and plasma etch dicing process for a wafer having backside solder bumps are described. For example, a method of dicing a semiconductor wafer having integrated circuits on a front side thereof and corresponding arrays of metal bumps on a backside thereof involves applying a dicing tape to the backside of the semiconductor wafer, the dicing tape covering the arrays of metal bumps. The method also involves, subsequently, forming a mask on the front side of the semiconductor wafer, the mask covering the integrated circuits. The method also involves forming scribe lines on the front side of the semiconductor wafer with a laser scribing process, the scribe lines formed in the mask and between the integrated circuits. The method also involves plasma etching the semiconductor wafer through the scribe lines to singulate the integrated circuits, the mask protecting the integrated circuits during the plasma etching.

What is claimed is: 
     
       1. A method of dicing a semiconductor wafer comprising integrated circuits on a front side thereof and corresponding arrays of metal bumps on a backside thereof, the method comprising:
 applying a dicing tape to the backside of the semiconductor wafer, the dicing tape covering the arrays of metal bumps; and, subsequently, 
 forming a mask on the front side of the semiconductor wafer, the mask covering the integrated circuits; 
 forming scribe lines on the front side of the semiconductor wafer with a laser scribing process, the scribe lines formed in the mask and between the integrated circuits; and 
 plasma etching the semiconductor wafer through the scribe lines to singulate the integrated circuits, the mask protecting the integrated circuits during the plasma etching. 
 
     
     
       2. The method of  claim 1 , wherein applying a dicing tape to the backside of the semiconductor wafer comprises vacuum laminating the dicing tape onto the arrays of metal bumps. 
     
     
       3. The method of  claim 1 , wherein the dicing tape is a UV-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by irradiating the UV-curable tape with UV light. 
 
     
     
       4. The method of  claim 1 , wherein the dicing tape is a thermally-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by heating the thermally-curable tape. 
 
     
     
       5. The method of  claim 1 , wherein the mask is a water-soluble mask, the method further comprising:
 subsequent to singulating the integrated circuits, removing the water-soluble mask with an aqueous-based treatment. 
 
     
     
       6. The method of  claim 1 , wherein the front side of the semiconductor wafer is mounted on a carrier tape during the applying the dicing tape to the backside of the semiconductor wafer, the method further comprising:
 demounting the semiconductor wafer from the carrier tape prior to forming the mask on the front side of the semiconductor wafer. 
 
     
     
       7. The method of  claim 6 , wherein the carrier tape is a UV-curable tape, and demounting the semiconductor wafer from the carrier tape comprises curing the UV-curable tape by irradiating with UV light. 
     
     
       8. The method of  claim 1 , wherein forming the scribe lines with the laser scribing process comprises forming trenches partially into the front side of the semiconductor wafer, and plasma etching the semiconductor wafer through the scribe lines comprises forming corresponding trench extension in the semiconductor wafer. 
     
     
       9. A method of dicing a semiconductor wafer comprising integrated circuits on a front side thereof and corresponding arrays of metal bumps on a backside thereof, the method comprising:
 providing the semiconductor wafer having a dicing tape applied to the backside thereof, the dicing tape covering the arrays of metal bumps, the semiconductor wafer also having a mask formed on the front side thereof, the mask covering the integrated circuits; 
 forming scribe lines on the front side of the semiconductor wafer with a laser scribing process, the scribe lines formed in the mask and between the integrated circuits; and 
 plasma etching the semiconductor wafer through the scribe lines to singulate the integrated circuits, the mask protecting the integrated circuits during the plasma etching. 
 
     
     
       10. The method of  claim 9 , wherein the dicing tape is a UV-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by irradiating the UV-curable tape with UV light. 
 
     
     
       11. The method of  claim 9 , wherein the dicing tape is a thermally-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by heating the thermally-curable tape. 
 
     
     
       12. The method of  claim 9 , wherein the mask is a water-soluble mask, the method further comprising:
 subsequent to singulating the integrated circuits, removing the water-soluble mask with an aqueous-based treatment. 
 
     
     
       13. The method of  claim 9 , wherein forming the scribe lines with the laser scribing process comprises forming trenches partially into the front side of the semiconductor wafer, and plasma etching the semiconductor wafer through the scribe lines comprises forming corresponding trench extension in the semiconductor wafer. 
     
     
       14. The method of  claim 9 , wherein a void between the backside of the semiconductor wafer and the dicing tape has a pressure substantially less than 1 atm. 
     
     
       15. A method of dicing a semiconductor wafer comprising integrated circuits on a front side thereof and corresponding arrays of metal bumps on a backside thereof, the method comprising:
 providing the semiconductor wafer having a dicing tape applied to the backside thereof, the dicing tape covering the arrays of metal bumps, the semiconductor wafer also having a mask formed on the front side thereof, the mask covering the integrated circuits, wherein scribe lines are formed in the mask and between the integrated circuits; and 
 plasma etching the semiconductor wafer through the scribe lines to singulate the integrated circuits, the mask protecting the integrated circuits during the plasma etching. 
 
     
     
       16. The method of  claim 15 , wherein the dicing tape is a UV-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by irradiating the UV-curable tape with UV light. 
 
     
     
       17. The method of  claim 15 , wherein the dicing tape is a thermally-curable tape, the method further comprising:
 subsequent to singulating the integrated circuits, demounting the integrated circuits from the dicing tape by heating the thermally-curable tape. 
 
     
     
       18. The method of  claim 15 , wherein the mask is a water-soluble mask, the method further comprising:
 subsequent to singulating the integrated circuits, removing the water-soluble mask with an aqueous-based treatment. 
 
     
     
       19. The method of  claim 15 , wherein the scribe lines include trenches formed partially into the front side of the semiconductor wafer, and plasma etching the semiconductor wafer through the scribe lines comprises forming corresponding trench extension in the semiconductor wafer. 
     
     
       20. The method of  claim 15 , wherein a void between the backside of the semiconductor wafer and the dicing tape has a pressure substantially less than 1 atm.